Apple launched a study to look for irregular heart rhythms on the Apple Watch

Apple and Stanford have teamed up for a new heart health study. Using a new Apple Watch app and the Apple Watch’s built-in sensor, researchers will work to identify irregular heart rhythms and notify users who may be experiencing atrial fibrillation (AFib).

AFib is the most common type of irregular heartbeat and can lead to heart failure or even stroke if left unchecked. The condition affects an estimated 3 million Americans (though some think those numbers may be higher) and approximately 33.5 million people around the world (or .5 percent of the world’s population).

Though the Watch can’t diagnose any conditions just yet, it is perfectly positioned to detect an irregular heart beat and alert those with a serious condition who may want to check it out further with a medical professional. That’s because, unlike some other heart rate checkers, it stays on the person most of the time and the Watch’s sensor flashes its LED green lights hundreds of times per second to detect the amount of blood flowing through the wrist and thus capture any abnormal heart behavior.

“Every week we receive incredible customer letters about how Apple Watch has affected their lives, including learning that they have AFib. These stories inspire us and we’re determined to do more to help people understand their health,” said Apple’s COO Jeff Williams. “Working alongside the medical community, not only can we inform people of certain health conditions, we also hope to advance discoveries in heart science.”

However, this is not the first heart health study to use the Apple Watch. Over the past year and a half, Cardiogram has been using its own algorithm and the Watch’s sensor in a study involving heart health with the University of California San Francisco.

So far, the Cardiogram’s study results seem promising. From that study, researchers were able to determine the Apple Watch could detect an abnormal heart rhythm with a 97 percent accuracy when paired with an AI-based algorithm called DeepHeart.

Later, the same eHealth study concluded the Watch could also detect sleep apnea and hypertension with similar accuracy using its built-in sensor.

That same ongoing study has also concluded the same results may be available to any wearable heart rate sensor, including those found within Garmin, Fitbit or Android Wear as they all have similar components. However, the study focused solely on results from the Apple Watch.

Currently, the only real way to diagnose AFib is through an ECG reading, which is usually done through equipment with a built-in ECG reader at a hospital or clinic. That is, unless you have an FDA approved ECG reader you can carry with you. So far, AliveCor has the only commercially available ECG reader consumers are able to carry with them via smartphone or, as of this morning, as a built-in sensor on the Apple Watch band.

The Apple Watch’s optical heart rate sensor is instead based on photoplethysmography (PPG), which can pick up on the second signal, irregular spacing between heart beats and it is not FDA approved for diagnosis of any heart condition.

However, just having the Watch or another sensor good enough to detect an issue could help alert someone that something is wrong and, as mentioned above, prompt them to go in for further evaluation.

“Through the Apple Heart Study, Stanford Medicine faculty will explore how technology like Apple Watch’s heart rate sensor can help usher in a new era of proactive health care central to our Precision Health approach,” Stanford school of medicine dean Lloyd Minor said in a press release.

Those ages 22 and over and who might have an irregular heart beat can participate in the new Apple heart health study by installing the app on any iOS device.